Our cities are 1.______ (crowd). Now cities are full of cars. Something will have to be 2.______ (do) to change it. What will the cars of tomorrow be like? Little cars may someday take the place of 3.______ (today) big cars. If everyone 4.______ _ (drive) little cars in the future, there will be less 5.______ (pollute) in the air. We can 6.______ ( breath) clean and fresh air. There will also be more space for 7.______ (park) cars in cities, and the 8.______ (street) will be less crowded. The space for a usual car 9.______ we use today is enough for little cars. The little cars will cost much less to own and be 10.______ (safe) to drive. What is more, these little cars can go about 65 kilometers per hour.